UNIVERSITY    OF   CALIFORNIA 

COLLEGE    OF    AGRICULTURE 

AGRICULTURAL   EXPERIMENT  STATION 

CIRCULAR  No.  251 

August,  1922 


RECOMMENDATIONS 
CONCERNING  THE 

COMMON  DISEASES  AND  PARASITES 

OF 

POULTRY  IN  CALIFORNIA 


By  J.  R.  BEACH  and  S.  B.  FREEBORN 


University  of  California,  Avian  Pathology  Laboratory, 
Petaluma,  California. 


Z  UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 

CONTENTS  page 

Introduction 2 

General  preventive  measures 2 

Chicken-pox  and  canker  or  avian  diptheria 5 

Colds  and  roup 13 

Nutritional  disease  resembling  roup 15 

Fowl  cholera  associated  with  ruptured  egg  yolk 19 

Tuberculosis 20 

Coccidiosis 22 

White  diarrhoea  of  chicks 25 

Leg  weakness  of  chicks 27 

Blackhead  in  turkeys 27 

Common  diseases  of  birds 30 

Lice 31 

Mites 33 

Ticks 37 

Fleas 38 

Flies 39 

Tapeworms 40 

Roundworms 42 

Cecum  worms         44 

INTRODUCTION 

There  are  a  number  of  diseases  and  parasites  which  may  attack 
poultry  and  cause  severe  loss.  The  modern  practice  of  raising  large 
numbers  of  fowls  continuously  on  relatively  small  areas  has  increased 
the  liability  of  their  occurrence.  It  is  obvious,  therefore,  that  some 
knowledge  of  the  means  of  recognizing,  preventing,  and  controlling 
the  more  common  diseases  and  parasites  is  of  great  importance  to  all 
poultry  raisers. 

GENERAL    PREVENTIVE    MEASURES 

The  most  effective  means  of  combating  diseases  and  parasites  of 
all  species  of  animals  is  to  prevent  their  occurrence.  This  principle  is 
especially  applicable  to  poultry  because  fowls  are  commonly  kept  in 
such  large  flocks  that  disease  may  spread  very  rapidly,  and  cause  con- 
siderable loss  before  it  is  recognized.  Furthermore,  the  value  of  a 
single  fowl  is  so  small  that  it  is  impractical  to  administer  individual 
treatment  to  many  sick  ones. 

Disease  is  very  often  introduced  by  new  stock.  This  is  more  apt 
to  occur  with  grown  birds  than  with  chicks.  It  is  safest,  therefore, 
for  a  beginner  to  buy  hatching  eggs  or  day-old  chicks.  Adult  "birds 
which  are  added  to  existing  flocks  should  be  kept  separate  for  at  least 
two  weeks  before  they  arc  put  with  the  others.  Even  with  this  pre- 
caution the  presence  of  some  infectious  diseases,  such  as  tuberculosis, 
may  be  overlooked. 

Feeding  methods  are  responsible  for  the  sickness  and  death  of 
birds  in  many  flocks.     Frequently  losses  from  this  cause  are  so  numer- 


Circular  251]  POULTRY  DISEASES  AND  PARASITES  3 

ous  as  to  resemble  the  effect  of  an  infectious  disease.  It  is  quite  appar- 
ent, therefore,  that  proper  feeding  of  fowls  is  an  important  factor  in 
disease  prevention. 

The  soil  of  yards  in  which  diseased  fowls  or  those  infested  with 
intestinal  parasites  are  kept  soon  becomes  contaminated  with  disease 
germs  or  parasite  eggs.  By  this  means  disease  and  parasites  may  be 
spread  to  other  fowls  placed  in  the  same  yards.  Parasite  eggs  may 
remain  alive  for  years,  but  most  disease  germs  which  affect  fowls  will 
die  in  a  few  months  if  the  yards  are  not  used.  The  danger  of  infection 
from  this  source  will  be  greatly  reduced  if  fowls  are  kept  but  a  few 
months  at  a  time  in  the  same  yards.  The  "double-yard  system"  which 
provides  two  yards  for  each  house  should  be  adopted.  This  will  permit 
fowls  to  be  kept  in  one  yard  while  the  other  is  being  plowed  and 
cropped.  It  is  also  desirable  that  the  soil  be  of  a  light  sandy  type  and 
well  drained,  rather  than  of  a  heavy  type  or  poorly  drained.  Water 
holes  in  the  yards  especially  are  to  be  avoided. 

The  type  of  poultry  house  may  have  considerable  bearing  on  the 
occurrence  of  disease.  Sunlight  is  one  of  the  most  effective  germ 
destroyers.  Houses  should  therefore  be  so  constructed  and  located 
that  the  direct  rays  of  the  sun  will  reach  all  parts  some  time  during 
each  day.  Other  essential  points  are  to  provide  good  ventilation  with- 
out draftiness,  to  make  provision  for  keeping  out  rain  during  stormy 
weather,  and  to  provide  drainage  away  from  the  house  so  that  the 
floors  will  not  become  damp.  It  is  also  desirable  to  have  the  house  so 
arranged  that  all  parts  can  be  easily  cleaned  and  to  have  all  nest  boxes, 
feed  troughs,  etc.,  removable. 

The  symptoms  caused  by  some  different  diseases  are  so  similar  that 
it  is  not  always  possible,  by  symptoms  alone,  to  differentiate  between 
an  infectious  and  a  non-infectious  one.  Therefore,  any  sick  fowls 
should  be  regarded  with  suspicion  and  be  removed  from  the  flock  as 
soon  as  discovered.  Strict  adherence  to  this  practice  will  assist  in 
preventing  serious  outbreaks  of  infectious  diseases.  A  sick  fowl  either 
should  be  isolated  in  comfortable  quarters  and  given  proper  care  and 
treatment,  or  destroyed.  It  should  not  be  simply  taken  out  of  the 
flock  and  allowed  to  roam  around  the  farm  at  will.  A  fowl  that  is 
very  sick  or  of  questionable  value  as  a  producer  should  be  destroyed 
rather  than  given  treatment. 

The  presence  of  most  infectious  diseases  and  internal  parasites  can 
be  best  determined  by  autopsy  of  a  dead  fowl.  It  is  a  good  practice, 
therefore,  to  make  an  examination  of  all  that  die  or  are  killed  on 
account  of  sickness.  By  such  examination  the  presence  of  disease  or 
parasites  can  be  detected  before  they  have  made  serious  progress  in 


UNIVERSITY    OF   CALIFORNIA — EXPERIMENT   STATION 


the  flock.     All  dead  fowls  should  be  disposed  of  by  burning  or  deep 
burial  in  a  place  to  which  the  fowls  do  not  have  access. 

Sanitation  is  essential  for  the  maintenance  of  health  in  any  flock. 
Under  this  heading  is  included  cleanliness  and  the  application  of  dis- 


Fig.  1. — Chicken-pox;   cockerel.     Natural  infection. 

infectants  and  parasiticides.  Cleanliness  is  perhaps  the  most  impor- 
tant of  the  three.  By  thorough  cleaning,  many  of  the  disease  germs 
and  parasite  eggs  will  be  removed.  Droppings  of  fowls  are  especially 
dangerous  as  a  spreader  of  disease.  It  is  quite  important,  therefore, 
that  droppings  either  should  be  removed  daily  or  roosts  so  constructed 
that  the  fowls  do  not  have  access  to  the  droppings  during  the  day. 
Litter  should  be  removed  and  floors  cleaned  frequently.  Drinking 
appliances  should  be  emptied  and  cleaned  daily.  If  moist  mash  is 
fed  the  troughs  should  be  cleaned  daily. 


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POULTRY  DISEASES  AND  PARASITES 


Disinfectant  should  be  applied  only  after  a  thorough  cleaning.  If 
applied  to  a  dirty  house,  it  will  not  penetrate  the  accumulations  of 
filth  and  therefore,  little  benefit  will  be  derived.  Disinfectants  are 
most  effective  when  applied  in  liberal  amounts  and  sprayed  with  con- 
siderable force  to  all  parts  of  the  house  from  all  directions  so  that  the 
bottom  of  cracks  will  be  reached.  Most  disinfectants  cannot  be  relied 
upon  to  destroy  parasites  such  as  mites  and  ticks,  for  which  purpose 
oily  preparations  are  more  effective.  A  ' '  compound  solution  of  cresol ' ' 
containing  50  per  cent  cresylic  acid  is  a  very  reliable  disinfectant. 
There   are  many  such   preparations   marketed   under   various   trade 


Fig.  2. — Chicken-pox;   baby  chick.     Natural  infection. 

names.  The  coal  tar  "sheep  dips"  are  cheapest  and  quite  effective. 
The  "phenol  coefficient"  which  is  usually  given  on  the  container  is 
an  index  of  the  efficiency  of  such  products.  Preparations,  such  as 
crude  carbolic  acid,  are  variable  in  their  germicidal  properties  and, 
therefore,  are  not  reliable  disinfectants. 


CHICKEN-POX   AND   CANKER    OR   AVIAN    DIPHTHERIA 

Chicken-pox  is  manifested  by  small  wart-like  growths  on  the  comb, 
wattles,  or  skin  of  the  head,  and  by  the  formation  of  masses  of  cheesy 
material  or  canker  in  the  eyes  and  the  mouth.  Although  these  last 
named  lesions  are  entirely  different  in  character  from  the  lesions  on 
the  skin  they  are  due  to  the  same  cause,  namely,  the  virus  of  chicken- 


b  UNIVERSITY   OF    CALIFORNIA EXPERIMENT   STATION 

pox.*  This  disease  cannot  occur  unless  the  chicken-pox  virus  is 
present,  although  unsanitary  conditions  and  poor  methods  of  care  and 
housing  make  it  more  likely  to  occur. 

Outbreaks  of  chicken-pox  vary  greatly  in  severity.  In  some  flocks 
but  a  few  birds  may  be  affected  and  practically  no  loss  result,  while 
in  other  flocks  the  lesions  may  be  very  severe ;  it  may  spread  through 


Fig.  3. — Canker-eye,  from  natural  infection  with  chicken-pox  virus. 

almost  the  entire  flock  and  cause  a  very  great  loss,  both  from  decreased 
egg  production  and  from  the  death  of  the  infected  fowls.  In  outbreaks 
in  which  a  large  percentage  of  the  infected  fowls  have  canker  the  loss 
will  be  greater  than  in  flocks  in  which  the  lesions  are  largely  on  the 
skin. 


*  Lesions  in  the  mouth  and  eyes  identical  in  appearance  to  canker  may  be 
caused  by  injury  to  the  mucous  membrane.  Therefore,  individual  cases  of  canker 
may  be  due  to  a  particle  of  litter,  barley  awn,  weed  seed,  or  similar  material  be- 
coming lodged  in  the  corner  of  the  eye,  the  cleft  in  the  roof  of  the  mouth  or  in  the 
larynx. 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


For  the  treatment  and  prevention  of  chicken-pox  and  canker,  vacci- 
nation is  believed  to  be  most  effective.  The  use  of  the  chicken-pox 
vaccine  has  been  very  extensive  in  this  state  for  several  years  past 
and  the  results  obtained  from  vaccination  have  been  very  satisfactory. 
One  treatment  is  usually  sufficient  to  check  the  spread  of  the  disease 
in  slightly  infected  flocks,  although  a  second  treatment  is  sometimes 
required.  In  badly  infected  flocks  a  second  treatment  given  seven 
days  after  the  first  is  always  advised.  Vaccine  should  be  used  on  all 
birds  in  the  flock  as  soon  as  the  presence  of  chicken-pox  in  the  flock  is 


Fig.  4. — Chicken-pox  and  canker  of  the  eye,  from  natural  infection  with  chicken- 
pox  virus. 


noticed.  It  is  never  recommended  to  vaccinate  fowls  before  the  appear- 
ance of  the  disease  among  them.  The  reason  for  this  recommendation 
is  that  the  length  of  time  after  vaccination  that  fowls  are  protected 
against  the  disease  is  variable  and  after  healthy  flocks  are  vaccinated 
there  is  therefore  no  assurance  that  they  will  be  protected  longer  than 
three  or  four  months.  If  a  flock  is  divided  into  a  number  of  small 
pens  and  are  under  close  observation,  it  may  not  be  necessary  to  vac- 
cinate the  entire  flock  upon  the  appearance  of  the  disease  but  only  the 


UNIVERSITY   OF    CALIFORNIA EXPERIMENT   STATION 


Figs.  5  and  6. — Chicken-pox;  turkey.     Natural  infection. 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


pens  that  are  affected.  In  such  cases  the  vaccine  would  be  used  on 
other  pens  as  soon  as  the  disease  appears. 

If  the  vaccine  is  properly  administered  it  does  not  seem  to  have 
any  harmful  effect  on  the  general  condition  of  the  birds.  The  egg 
yi^ld,  however,  is  usually  somewhat  decreased  for  a  short  time  after 
vaccination,  but  as  a  rule  this  decrease  will  be  no  greater  than  would 
be  expected  if  the  fowls  were  handled  for  any  other  reason. 

The  vaccine  is  administered  by  injection  beneath  the  skin  with  a 
hypodermic  syringe.     The  dose  is  one  cubic  centimeter  for  each  bird. 


Fig.  7. — Canker  of  the  mouth,  turkey;  from  natural  infection  with  chicken-pox 
virus. 


The  most  convenient  place  for  administration  is  beneath  the  skin  of  the 
breast,  under  the  right  thigh,  the  skin  at  that  point  being  compara- 
tively free  from  feathers.  When  the  operator  holds  the  bird  the  left 
wing  is  held  back,  the  foAvl  laid  on  its  left  side,  and  the  right  wing  and 
leg  and  feet  held  back  with  the  last  three  fingers  of  the  left  hand.  The 
exposed  skin  is  then  cleansed  with  a  piece  of  absorbent  cotton  saturated 
with  a  disinfectant  solution  (2  per  cent  compound  solution  of  cresol) 
and  picked  up  with  the  thumb  arid  forefinger  of  the  left  hand.  Then 
with  the  right  hand  the  syringe  needle  is  inserted  just  beneath  the  skin 
and  the  proper  dose  injected.  With  a  little  practice,  one  man  with  an 
assistant  to  catch  the  birds  can  vaccinate  from  100  to  150  birds  per 
hour.  When  an  assistant  holds  the  bird,  both  wings  are  grasped  with 
the  left  hand  and  both  legs  with  the  right  hand.     The  bird  is  then 


10 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 


laid  on  its  left  side  with  the  breast  towards  the  operator.  The  operator 
standing  a  little  to  the  rear  of  the  bird,  cleanses  the  skin  at  the  point 
of  injection,  picks  it  up  with  the  thumb  and  forefinger  of  the  left  hand, 
and  with  the  right  hand  inserts  the  syringe  needle  just  beneath  the 
skin  and  injects  the  vaccine.  By  this  method  a  man  with  two  assist- 
ants to  catch  and  hold  the  birds,  can  vaccinate  from  200  to  300  birds 
per  hour. 


Fig.  8. — Method  of  holding  a  fowl  and  injecting  chicken-pox  vaccine. 


Fig.  9. — Materials  required  for  vaccination. 


Circular  251] 


POULTRY  DISEASES  AND  PABASITES 


11 


lu  inserting  the  needle  strict  precaution  should  be  taken  that  it  go 
just  beneath  the  skin  and  not  at  all  in  the  breast  muscle.  The  safest 
practice  to  follow  is  to  have  a  sufficient  area  of  skin  exposed  so  that 
the  point  of  the  needle  will  always  be  in  sight  through  the  skin  before 
any  vaccine  is  injected.  A  syringe  of  6  to  12  c.c.  capacity  is  well 
suited  for  this  work.  The  needle  should  be  16  to  18  gauge  and  from 
iy2  to  2  inches  in  length.  A  screw  needle  is  preferable.  Vaccine 
deteriorates  rapidly  and  should  be  used  within  seven  days  of  its  manu- 


Fig.  10. — Method  of  holding  a  fowl  and  removing  canker  from  the  mouth. 


facture.  If  old  or  decomposed  vaccine  is  used,  poor  results  will  follow. 
Vaccine  should  be  kept  in  a  cool  place,  preferably  on  ice,  until  used 
and  only  one  bottle  opened  at  a  time. 

The  materials  required  for  vaccination  are :  the  vaccine ;  a  syringe 
which  should  be  sterilized  by  boiling  before  using;  a  small  wide- 
mouth,  covered  vessel,  such  as  a  quarter-pint  milk  bottle  provided  with 
a  stopper,  or  a  jelly  glass  with  a  tight  fitting  cover,  which  is  used  as  a 
vaccine  container  from  which  to  fill  the  syringe  and  which  should 
be  sterilized  by  boiling  before  using;  a  pan  of  disinfectant;  and  a 
piece  of  absorbent  cotton  for  cleansing  the  skin  at  the  point  of  in- 


12 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


jection.  The  bottle  of  vaccine  should  always  be  thoroughly  shaken 
before  any  vaccine  is  poured  out  and  the  wide-mouth  container  should 
always  be  thoroughly  shaken  before  filling  the  syringe. 

The  immunizing  effect  of  vaccine  does  not  take  place  immediately. 
Therefore,  fowls  infected  at  the  time  of  vaccination  or  which  become 
infected  soon  after  will  develop  chicken-pox  lesions.  Such  cases  are 
usually  mild  and  will  soon  recover  if  the  fowls  are  removed  from  the 
flock  and  the  lesions  treated. 


Fig.  11. — Method  of  holding  a  fowl  and  removing  canker  from  the  eyes. 

All  diseased  birds  should  be  removed  from  the  flock  and  kept  in 
comfortable  quarters  where  they  can  be  given  treatment  at  two-  or 
four-day  intervals.  The  scabs  which  form  on  the  growths  on  the 
comb,  wattles,  or  skin  should  be  removed  with  a  dull  knife  or  a  pair 
of  forceps,  and  tincture  of  iodine  applied  to  the  exposed  suface.  Col- 
lections of  cheesy  material  in  the  mouth  should  be  removed  with 
forceps  and  tincture  of  iodine  applied.  Collections  of  cheesy  material 
within  the  eyelids  should  be  removed  by  pressing  around  the  eye  with 
the  thumb  and  finger  tips  and  tincture  of  iodine  applied.  If  the  cheesy 
material  adheres  to  the  eyeball,  it  will  be  necessary  to  use  forceps 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


13 


to  remove  it.  In  such  cases  the  eyeball  is  usually  destroyed  before  the 
recovery  is  complete.  Tincture  of  iodine  can  be  applied  most  con- 
veniently and  effectively  with  a  medicine  dropper.  It  will  not  in  any 
way  injure  the  eyesight  or  be  otherwise  injurious  to  the  birls.  The  ad- 
ministration of  vaccine  in  addition  to  local  treatment  with  iodine  will 
hasten  recovery  and  decrease  the  loss  from  death.  All  diseased  fowls 
should  be  given  two  or  more  doses  of  vaccine.* 


Fig.  12. — Fowl  with  roup. 


COLDS   AND    ROUP 

"Colds"  are  manifested  by  a  discharge  from  one  or  both  nostrils. 
When  this  discharge  collects  in  the  nasal  passages  it  is  rapidly  trans- 
formed into  a  cheesy  mass  which  causes  a  marked  swelling  of  the  face 
just  beneath  the  eyes.  This  stage  of  the  disease  is  called  "roup."  It 
can  be  easily  seen  that ' '  roup ' '  is  merely  the  result  of  a  cold.  If  fowls 
did  not  get  "colds,"  they  would  not  have  roup.  As  a  rule,  "colds" 
and  roup  are  confined  entirely  to  the  nasal  passages,  although  in  many 


*  Chicken-pox  vaccine  can  be  obtained  from  the  Division  of  Veterinary  Science, 
University  of  California,  at  the  actual  cost  of  production,  provided  the  applicant 
furnishes  satisfactory  evidence  that  chicken-pox  exists  among  his  fowls.  The 
present  cost  of  vaccine  is  l%c  per  dose.  Hypodermic  syringes  with  which  to 
administer  the  vaccine  can  also  be  procured  from  the  University  at  a  cost  of  $3.50 
each.  All  applicants  should  specify  in  writing  the  amount  of  vaccine  desired  or 
the  number  of  fowls  to  be  treated.  Vaccine  will  be  shipped  only  when  cash 
accompanies  the  order,  or  C.  O.  D.  When  possible,  orders  will  be  shipped  the  same 
day  they  are  received. 


14  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION 

cases  the  eyelids  may  become  closed  by  the  large  swellings  beneath 
them.  Seldom,  however,  are  the  eyes  affected  in  any  other  way.  This 
disease  is  usually  the  result  of  housing  or  weather  conditions  and  not 
due  to  any  specific  infection.  Therefore,  it  is  not  liable  to  spread 
through  a  flock  by  contact  with  diseased  birds,  nor  is  it  liable  to  seri- 
ously affect  any  flock  that  it  properly  housed  and  cared  for.    Improper 


Fig.  13. — Method  of  relieving  "stoppage  of  the  tear  duct," 
commonly  called  "cold  in  the  eye." 

housing  conditions  are  probably  the  most  common  cause  of  colds. 
Common  faults  in  housing  conditions  are,  presence  of  cracks  in  the 
walls  back  of  the  roosts,  poor  ventilation,  overcrowding,  dampness,  and 
insanitation.  Extended  periods  of  damp,  cold  weather,  or  periods 
during  which  there  is  a  wide  variation  in  temperature  during  the  day 
and  night,  are  apt  to  cause  ' '  colds ' '  to  become  prevalent. 

Prevention  consists  in  correcting  any  faults  in  the  housing 
conditions,  giving  the  birds  proper  care,  and  keeping  the  premises 
sanitary. 


Circular  251]  POULTRY  DISEASES  AND  PARASITES  15 

A  satisfactory  treatment  for  individuals  consists  in  cleaning  out 
the  nostrils  by  pressing  with  the  fingers  and  cleaning  out  the  cleft 
with  absorbent  cotton  on  forceps  or  a  match,  and  applying  a  drop  of 
tincture  of  iodine  in  each  nostril  and  in  the  cleft.  This  treatment 
should  be  repeated  every  three  or  four  days.  The  treatment  for  roup 
is  more  difficult.  This  consists  in  opening  the  swelling  with  a  sharp 
knife,  removing  the  mass  of  cheesy  material  and  packing  the  cavity 
with  absorbent  cotton  saturated  with  tincture  of  iodine.  The  packing 
should  be  removed,  the  cavity  cleaned  and  a  new  pack  put  in  every 
five  to  seven  days.  If,  upon  removing  the  pack,  no  more  cheesy 
material  is  found  to  have  formed,  the  pack  may  be  left  out  and  the 
wound  allowed  to  heal. 

If  a  large  percentage  of  the  flock  have  colds  the  following  treat- 
ment may  be  used.  Give  Epsom  salts  in  the  drinking  water,  using 
one  pound  for  each  125  adults  or  200  to  400  birds  under  five  months 
of  age.  The  birds  should  have  access  to  no  other  drink  while  the 
solution  of  Epsom  salts  is  consumed.  Following  this,  potassium  per- 
manganate may  be  added  to  the  drinking  water  in  sufficient  quantity 
to  produce  a  deep  purple  color.  This  should  be  replaced  by  fresh 
solution  when  the  color  changes  to  brown.  Some  tonic,  such  as  the 
following,  may  be  added  to  the  mash : 

Pulverized  gentian  1  lb. 

Pulverized  ginger  %  lb. 

Pulverized  saltpeter  y±  lb. 

Pulverized  iron  sulphate  %  lb. 

Pulverized  nux  vomica  *4  lb. 

Add  one  ounce  of  this  mixture  to  each  five  pounds  of  mash  and 
feed  until  the  flock  has  recovered. 

If  faulty  housing  is  causing  colds  reliance  should  not  be  placed 
on  the  treatment  just  described. 

NUTRITIONAL    DISEASE    RESEMBLING    ROUP 

A  disease  very  similar  to  roup  in  manifestation,  which  may  affect 
a  large  percentage  of  a  flock  at  one  time,  may  be  due  to  nutritional 
factors.  The  symptoms  of  this  disease  are  weakness;  emaciation;  a 
discharge  from  one  or  both  nostrils  which  may  be  followed  by  a  swell- 
ing of  the  face  beneath  the  eyes ;  a  discharge  from  the  eyes  which  may 
glue  the  eyelids  together  and  be  followed  by  the  formation  of  an 
adherent  white  film  over  the  third  eyelid  and  a  mass  of  white  cheesy 
material  within  the  eyelids ;  the  formation  of  a  yellowish  white,  round, 
cheesy  pustule-like  patches  in  the  mouth  and  throat  of  about  the  size 


16 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


Fig.  14. — Typical  appearance  of  fowls  with  the  nutritional  disease  resembling  roup. 


Fig.    I"..    -Cheeky    materia]    m   the   eye  of  a  fowl  with   the   nutritional    disease 
resemoling  roup. 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


17 


Fig.    16. — Fowl    with    nutritional    disease    resembling    roup    with    throat 
oesophagus  opened  to  show  the  pustule-like  lesions  typical  of  the  disease. 


and 


18 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 


Fig.  17. — Kidneys  of  a  fowl  with  nutritional  disease  resembling  roup. 


Circular  251]  POULTRY  DISEASES  AND  PARASITES  19 

of  a  pinhead;  and  occasionally  by  the  formation  of  masses  of  white 
cheesy  material  in  the  cleft  or  elsewhere  in  the  mouth.  This  disease 
may  be  distinguished  from  chicken-pox  by  the  absence  of  yellow  color 
in  the  cheesy  material  and  by  the  small  size  of  the  patches  and  color 
of  the  cheesy  material  in  the  mouth.  It  may  be  distinguished  from 
"colds"  and  roup  by  the  lesions  in  the  eye  and  mouth,  in  addition 
to  nasal  discharge  and  swelling  of  the  face. 

Postmortem  examination  of  dead  birds  usually  shows  the  kidneys 
to  be  very  pale  and  marked  with  a  network  of  very  fine  white  lines. 
Occasionally  there  is  also  found  a  deposit  of  a  white  material  on  the 
surface  of  the  liver,  on  the  membrane  around  the  heart,  or  elsewhere 
on  the  surface  of  the  organs. 

It  has  been  very  definitely  determined  that  this  disease  may  result 
from  insufficient  supply  of  greens.  It  may  occur  even  though  the  birds 
may  be  fed  green  food  if  the  amount  is  insufficient.  It  has  also  been 
found  in  flocks  which  had  access  to  growing  greens,  but  which  were  at 
a  distance  from  the  poultry  house.  In  these  cases  some  of  the  fowls 
were  getting  a  sufficient  supply  of  greens  but  most  of  them  were  not 
going  far  enough  away  from  the  house  to  get  it. 

This  condition  can  usually  be  readily  controlled  by  giving  the  birds 
all  the  green  food  they  will  eat.  There  may  be  other  factors  involved 
in  producing  this  disease  and  it  is,  therefore,  also  advisable  to  dilute 
the  mash  by  adding  wheat  bran. 

FOWL  CHOLERA  ASSOCIATED  WITH  RUPTURED  EGG  YOLKS 

This  disease  usually  occurs  among  flocks  of  pullets  during  the 
period  of  heavy  production.  It  is  manifested  by  a  rather  small  but 
steady  loss  of  birds.  The  infected  fowls  are  usually  sick  but  a  very 
short  time  before  death  occurs  and  in  a  great  many  cases  are  found 
dead  rather  than  sick. 

The  symptoms  of  the  sick  birds  are  droopiness,  diarrhoea,  discolor- 
ation of  the  comb,  usually  followed  by  death  within  twenty-four  hours. 
Birds  may  be  found  dead  in  the  nests  or  on  the  dropping  boards  under 
the  roosts.    The  fowls  affected  are  those  that  are  laying  well. 

The  post-mortem  examination  of  dead  birds  usually  shows  an  en- 
larged, soft  liver  which  may  have  minute  yellowish  white  spots ;  some- 
times small  blood  spots  in  the  fat  at  the  base  of  the  heart  or  on  the 
gizzard;  sometimes  inflammation  of  the  intestines;  and  practically 
always  egg  yolk  free  in  the  abdominal  cavity.  The  egg  yolk  may  be 
like  one  freshly  broken  or  may  be  in  the  form  of  a  cheesy  mass.  In 
many  of  these  fowls  the  presence  of  fowl  cholera  germs  can  be  demon- 


20  UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 

strated.  The  germs  found  in  such  cases,  however,  are  of  such  low 
virulence  that  death  can  rarely  be  caused  by  feeding  or  inoculating 
healthy  birds  with  them. 

This  disease  appears  to  be  the  result  of  heavy  feeding  and  produc- 
tion, rather  than  entirely  to  infection  with  the  fowl  cholera  germ. 
Good  success  in  controlling  this  disease  has  been  obtained  by  adding 
wheat  bran  to  the  mash  to  make  it  bulkier.  This  will  automatically 
reduce  the  amount  by  weight  of  mash  consumed  and  should  also 
decrease  egg  production.    If  the  losses  have  been  very  heavy  the  mash 


Pig.  18. — Tuberculosis  nodules  on  the  intestines  and  liver  of  a  fowl. 

should  be  entirely  replaced  by  bran  until  losses  stop.  If,  however, 
not  many  birds  are  dying,  the  mash  can  be  made  one-half  bran.  It  is 
also  advisable  to  thoroughly  clean  and  disinfect  the  houses  and  to 
use  potassium  permanganate  in  sufficient  amount  to  give  the  drinking 
water  a  claret  color,  or  to  use  some  similar  disinfectant  in  the  drinking 
water.  A  one  to  two-thousand  solution  of  bichloride  of  mercury  is 
effective  and  safe.  This  must  be  used  only  in  wood,  glass,  or  earthen- 
ware vessels  and  must  be  kept  away  from  other  animals  or  from 
children. 

TUBERCULOSIS 

This  disease  is  caused  by  a  specific  germ  and  cannot  be  produced 
in  any  other  way.  Symptoms  of  infection  with  this  germ  are  appar- 
ent only  in  advanced  cases,  viz.,  marked  emaciation,  paleness  of  the 
comb,  skin,  or  shanks. 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


21 


The  lesions  of  tuberculosis  consist  of  round  yellow  spots  varying 
in  size  from  a  pinhead  to  a  pea  in  the  liver  and  spleen,  and  nodules 
varying  in  size  from  a  pea  to  a  small  walnut  on  the  intestines  or  on 
the  membrane  which  holds  the  intestines  in  place.  Lesions  also  occur 
less  frequently  in  the  kidneys,  lungs,  skin,  and  bones. 

Tuberculosis  spreads  by  fowls  eating  substances,  such  as  food  and 
soil  contaminated  by  the  discharges  from  the  infected  birds.     The  loss 


Fig.  19. — Fowl  showing  a  positive  reaction  to  the  tuberculin  test. 


from  tuberculosis  is  not  apt  to  be  great  at  any  one  time,  but  it  will  be 
constant  and  becomes  increasingly  severe  as  time  goes  on. 

There  are  two  possible  methods  of  eradicating  tuberculosis  from 
a  flock.  The  first  consists  in  disposing  of  all  birds  in  the  flock, 
thoroughly  cleaning  and  disinfecting  the  house,  leaving  the  yards 
vacant  for  a  period  of  a  few  months  and  starting  in  again  with  new 
stock.  If  the  yards  are  left  vacant  during  hot  or  dry  weather  one  or 
two  months  is  sufficient.  If,  however,  the  ground  is  moist,  from  six 
months  to  a  year  may  be  required  for  the  germs  to  die  out.     This  is 


22  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 

the  most  practical  method  to  use  in  small  flocks  or  flocks  which  are 
raised  solely  for  egg  production. 

The  other  method  of  eradicating  tuberculosis  is  by  means  of 
the  tuberculin  test.  This  test  is  made  by  injecting  y15  to  y2n  cubic 
centimeter  of  substance  known  as  tuberculin  into  the  skin  of  the 
wattle.  If  an  injected  bird  has  tuberculosis  the  wattle  will  swell. 
It  is  necessary  to  make  repeated  tests  at  intervals  of  about  six  months 
to  entirely  free  a  flock  from  tuberculosis  by  this  method.  Following 
each  test  all  reacting  birds  must  be  removed  from  the  flock  and  the 
houses  given  a  thorough  cleaning  and  disinfecting.  It  is  recommended 
to  use  this  test  only  in  flocks  that  are  valuable  as  breeders. 

COCCIDIOSIS 

This  is  an  infectious  disease  of  chicks  caused  by  the  presence  of 
minute  parasites  in  the  intestines.  It  may  affect  the  chicks  between 
the  ages  of  two  weeks  and  six  months,  but  more  commonly  it  occurs 
in  birds  four  to  eight  weeks  old.  The  usual  history  of  outbreaks  of 
coccidiosis  is  that  the  chicks  do  well  until  they  are  a  few  weeks  old, 
when  they  begin  to  look  unthrifty,  droop  and  gradually  die.  The 
symptoms  observed  are  ruffled  feathers,  paleness  of  the  skin  on  the 
heads  and  shanks,  and  an  inclination  of  sick  chicks  to  separate  them- 
selves from  the  flock  and  stand  "humped  up"  with  their  eyes  closed 
for  hours  at  a  time.  Diarrhoea  which  may  be  bloody  is  sometimes 
present.  A  bloody  diarrhoea  can  be  considered  as  positive  evidence 
of  coccidiosis.    Other  symptoms  are  not  so  characteristic  of  this  disease. 

Post-mortem  lesions  usually  consist  of  an  enlargement  of  the  ceca 
or  "blind  pouches"  of  the  intestines.  The  contents  may  be  either 
normal  in  consistency  and  brown  or  reddish  brown  in  color,  semi- 
liquid  and  bloody,  or  solid  and  yellowish  white,  brown  or  red  in  color. 
Frequently  there  is  an  inflammation  of  the  lining  of  the  intestines 
throughout  their  entire  length.  Other  organs  are  in  most  cases 
apparently  normal. 

The  disease  is  spread  by  chicks  drinking  water  or  eating  food,  litter 
or  soil  contaminated  by  the  droppings  of  diseased  chicks.  It  has  been 
demonstrated  that  these  parasites  will  remain  alive  in  soil  for  a  year 
or  more.  Therefore,  chicks  allowed  to  run  in  yards  in  which  infected 
chicks  were  kept  the  preceding  year  are  very  liable  to  become  infected. 
Thus  far  no  practical  method  of  treating  the  soil  to  destroy  these 
parasites  has  been  developed.  This  disease  can  be  prevented  and  out- 
breaks controlled  by  proper  feeding  methods  and  proper  sanitation  in 
the  brooder  houses. 


Circular  251]  poultry  diseases  and  parasites  23 


Fig.  20. — Typical  appearance  of  chicks  with  Coccidiosis. 


Pig.  21. — Ceca  or  blind  pouches  of  the  intestines  of  a  normal  chick  and  en- 
larged ceca  of  a  chick  with  Coccidiosis. 


22  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 

the  most  practical  method  to  use  in  small  flocks  or  flocks  which  are 
raised  solely  for  egg  production. 

The  other  method  of  eradicating  tuberculosis  is  by  means  of 
the  tuberculin  test.  This  test  is  made  by  injecting  y15  to  %0  cubic 
centimeter  of  substance  known  as  tuberculin  into  the  skin  of  the 
wattle.  If  an  injected  bird  has  tuberculosis  the  wattle  will  swell. 
It  is  necessary  to  make  repeated  tests  at  intervals  of  about  six  months 
to  entirely  free  a  flock  from  tuberculosis  by  this  method.  Following 
each  test  all  reacting  birds  must  be  removed  from  the  flock  and  the 
houses  given  a  thorough  cleaning  and  disinfecting.  It  is  recommended 
to  use  this  test  only  in  flocks  that  are  valuable  as  breeders. 

COCC1DIOSIS 

This  is  an  infectious  disease  of  chicks  caused  by  the  presence  of 
minute  parasites  in  the  intestines.  It  may  affect  the  chicks  between 
the  ages  of  two  weeks  and  six  months,  but  more  commonly  it  occurs 
in  birds  four  to  eight  weeks  old.  The  usual  history  of  outbreaks  of 
coccidiosis  is  that  the  chicks  do  well  until  they  are  a  few  weeks  old, 
when  they  begin  to  look  unthrifty,  droop  and  gradually  die.  The 
symptoms  observed  are  ruffled  feathers,  paleness  of  the  skin  on  the 
heads  and  shanks,  and  an  inclination  of  sick  chicks  to  separate  them- 
selves from  the  flock  and  stand  "humped  up"  with  their  eyes  closed 
for  hours  at  a  time.  Diarrhoea  which  may  be  bloody  is  sometimes 
present.  A  bloody  diarrhoea  can  be  considered  as  positive  evidence 
of  coccidiosis.    Other  symptoms  are  not  so  characteristic  of  this  disease. 

Post-mortem  lesions  usually  consist  of  an  enlargement  of  the  ceca 
or  "blind  pouches"  of  the  intestines.  The  contents  may  be  either 
normal  in  consistency  and  brown  or  reddish  brown  in  color,  semi- 
liquid  and  bloody,  or  solid  and  yellowish  white,  brown  or  red  in  color. 
Frequently  there  is  an  inflammation  of  the  lining  of  the  intestines 
throughout  their  entire  length.  Other  organs  are  in  most  cases 
apparently  normal. 

The  disease  is  spread  by  chicks  drinking  water  or  eating  food,  litter 
or  soil  contaminated  by  the  droppings  of  diseased  chicks.  It  has  been 
demonstrated  that  these  parasites  will  remain  alive  in  soil  for  a  year 
or  more.  Therefore,  chicks  allowed  to  run  in  yards  in  which  infected 
chicks  were  kept  the  preceding  year  are  very  liable  to  become  infected. 
Thus  far  no  practical  method  of  treating  the  soil  to  destroy  these 
parasites  has  been  developed.  This  disease  can  be  prevented  and  out- 
breaks controlled  by  proper  feeding  methods  and  proper  sanitation  in 
the  brooder  houses. 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


23 


Fig.  20. — Typical  appearance  of  chicks  with  Coccidiosis. 


Fig.  21. — Ceca  or  blind  pouches  of  the  intestines  of  a  normal  chick  and  en- 
larged ceca  of  a  chick  with  Coccidiosis. 


24  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION 

The  method  of  feeding  to  prevent  the  occurrence  of  the  disease  con- 
sists in  keeping  sour  milk  or  butter-milk  constantly  before  the  birds 
from  the  time  they  are  put  in  the  brooder,  and  feeding  sparingly 
of  grain  and  mash.  If  the  amount  of  grain  and  mash  fed  is  not 
restricted,  coccidiosis  is  liable  to  develop,  even  though  sour  milk  is 
fed  all  the  time. 

The  disease  frequently  occurs  in  previously  healthy  flocks  follow- 
ing sudden  changes  in  the  kind  of  grain  and  mash  fed.  Such  changes 
should,  therefore,  be  avoided.  Coccidiosis  also  often  appears  soon  after 
an  exceptionally  cold  night  or  following  a  severe  storm  which  has 
caused  the  brooder  to  become  cold  or  damp.  It  is  essential,  therefore, 
that  houses  be  kept  clean  and  dry  and  that  adequate  temperature  be 
maintained  at  all  times. 

To  control  outbreaks  of  the  disease  no  mash  and  very  little  grain 
should  be  fed.  The  bulk  of  the  grain  fed  should  be  given  at  night  so 
that  the  chicks  will  have  a  fairly  full  crop  when  they  go  to  bed.  A 
small  amount  of  grain  may  be  fed  in  the  morning,  but  the  greater  part 
of  the  food  in  the  daytime  should  consist  of  sour  milk  or  butter-milk 
which  is  kept  before  them  constantly.  The  houses  should  be  very 
thoroughly  cleaned  and  covered  with  a  thin  layer  of  chopped  straw 
or  shavings  litter.  Feeding  large  amounts  of  sour  milk  will  cause 
the  droppings  to  become  very  profuse  and  watery.  In  order  to  keep 
the  floor  clean  and  dry  the  litter  should,  therefore,  be  renewed  daily. 
Abundant  warmth  should  be  maintained  both  under  the  hover  and  in 
the  brooder  rooms. 

This  feeding  method  should  be  continued  until  losses  stop  and  the 
general  condition  of  the  flock  has  improved.  This  usually  will  not 
require  more  than  a  week  or  ten  days.  After  this  time  the  mash  may 
be  again  fed  but  the  amount  should  be  small  and  increased  very  grad- 
ually. Although  no  experiments  have  been  made  it  is  thought  that 
some  of  the  better  varieties  of  sour  milk  substitutes,  such  as  semi-solid 
butter-milk,  will  give  as  good  results  as  butter-milk.  Other  remedies 
which  have  been  recommended  are  hydrochloric  acid,  one  teaspoonful 
to  one  quart  of  water,  potassium  bichromate  1  to  5000  solution,  and 
crude  catechu  1  to  4000  solution.  The  solutions  of  the  above  chemicals 
are  substituted  for  the  drinking  water.  If  any  of  these  are  used  the 
amount  of  mash  fed  should  be  reduced. 


Circular  251]  POULTRY  DISEASES  AND  PARASITES  25 


WHITE    DIARRHOEA    OF    CHICKS 

Disease  manifested  by  diarrhoea  is  of  common  occurrence  in  young 
chicks.  Since  the  discharges  from  the  intestines  in  such  cases  are  light- 
colored,  any  trouble  of  this  nature  is  usually  designated  as  "white 
diarrhoea."  White  diarrhoea  may  be  caused  either  by  infection  with 
a  specific  germ  or  by  some  error  in  incubation  or  brooding.  Infectious 
white  diarrhoea,  which  is  known  as  "bacillary  white  diarrhoea,"  is 
caused  by  a  germ  and  cannot  be  produced  in  any  other  way.  The 
symptoms  are  usually  the  same  whether  the  disease  is  infectious  or  not 
infectious. 

"Bacillary  white  diarrhoea"  occurs  in  chicks  hatched  from  eggs 
produced  by  infected  breeding  stock.  Chicks  which  are  infected  with 
bacillary  white  diarrhoea  and  do  not  die,  continue  to  harbor  the  germs 
throughout  their  lifetime.  Such  hens  do  not  show  any  indication  of 
infection ;  are  apparently  in  perfect  health  and  are  often  good  layers. 
They  therefore  frequently  get  into  breeding  flocks.  Eggs  produced 
by  such  hens  contain  the  germs  on  the  inside.  The  chick  hatched  from 
such  an  egg  will  be  infected  when  it  comes  out  of  the  shell  and  may 
quickly  spread  the  infection  to  other  chicks  in  the  incubator. 

The  disease  usually  appears  during  the  first  week  but  losses  may 
continue  for  three  or  four  weeks.  The  mortality  is  usually  high,  on  an 
average  more  than  50  per  cent.  There  is  no  satisfactory  method  of 
treating  bacillary  white  diarrhoea.  Sanitary  precautions,  such  as 
removal  and  destruction  of  the  sick  and  dead  chicks,  thorough  clean- 
ing and  disinfection  of  the  brooders,  and  dividing  of  the  remaining 
chicks  into  small  units,  will  assist  in  reducing  the  mortality.  There 
are  no  drugs  which  are  of  any  value  for  this  purpose. 

Bacillary  white  diarrhoea  can  be  prevented  by  using  only  eggs  for 
hatching  which  are  known  to  be  produced  by  a  flock  free  from  the 
infection.  If  a  poultry  breeder  has  had  no  trouble  with  bacillary 
white  diarrhoea  in  his  own  chicks  or  in  chicks  hatched  by  others  from 
eggs  produced  by  his  flock,  this  may  be  taken  as  evidence  that  his 
flock  is  not  infected.  It  is  also  possible  to  determine  whether  or  not 
a  flock  is  infected  by  means  of  a  blood  test.  This  test  must  be  made  in 
a  laboratory  with  a  sample  of  blood  procured  from  the  bird.  It  is 
advisable  to  have  such  a  test  made  on  all  new  breeding  stock  unless  it 
is  known  that  the  flock  from  which  the  stock  was  procured  is  free  from 
the  infection. 

White  diarrhoea  that  is  due  to  errors  in  incubation  and  brooding 
can  not  be  differentiated  by  symptoms  or  post-mortem  appearance  from 
infectious  white  diarrhoea.    Therefore,  to  determine  positively  whether 


26 


UNIVERSITY    OF   CALIFORNIA EXPERIMENT   STATION 


Figs.  22  and  23. — Securing  blood  for  the  agglutination  test  for  bacillary  white 
diarrhoea  infection  in  breeding  stock. 


Circular  251]  POULTRY  DISEASES  AND  PARASITES  27 

or  not  infection  is  present,  it  is  necessary  to  have  a  bacteriological 
examination  made.  Among  errors  in  incubation  or  brooding  which 
may  cause  diarrhoea  are,  overheating  or  chilling  in  the  incubator, 
overheating  or  chilling  in  the  brooder,  and  too  early  and  improper 
feeding.  The  most  effective  means  of  treating  chicks  with  non- 
infectious white  diarrhoea  is  to  give  them  the  best  possible  care  and 
proper  food.    The  use  of  sour  milk  or  butter-milk  is  always  advisable. 

LEG    WEAKNESS    OF   CHICKS 

Leg  weakness  is  generally  considered  to  be  caused  by  improper 
feeding.  The  possible  errors  in  feeding  are  feeding  too  much,  feeding 
a  ration  insufficient  in  mineral  matter,  or  feeding  a  ration  lacking  iu 
fiber.  Lack  of  exercise  or  confining  the  chicks  in  the  houses  is  also 
thought  to  be  a  contributory  factor  in  producing  the  disease.  It  is 
unlikely  to  occur  if  flocks  are  fed  a  properly  compounded  ration,  are 
not  crowded  in  the  brooder  house,  and  are  allowed  to  run  out  of  doors 
early. 

When  the  disease  does  occur  it  may  be  controlled  by  making 
changes  in  the  ration  and  the  method  of  handling.  If  the  ration  is 
too  rich  or  does  not  contain  enough  fiber,  it  may  be  corrected  by  adding 
wheat  bran.  As  the  amount  of  bran  to  be  added  varies  with  the  con- 
ditions a  general  recommendation  would  be  to  use  equal  parts  of  the 
mash  and  bran.  Mineral  matter  may  be  supplied  by  sprinkling  pre- 
cipitated calcium  phosphate  over  the  surface  of  the  mash  after  it  has 
been  put  into  the  trough  or  hopper.  An  abundance  of  green  food 
should  always  be  provided.  If  the  chicks  have  been  confined  in  the 
houses  they  should  be  allowed  to  run  outdoors  every  day  that  the  sun 
is  shining.  They  should,  of  course,  not  be  kept  out  when  they  show 
evidence  of  being  chilled,  but  they  can  be  put  out  for  at  least  a  few 
minutes  each  day  and  the  time  can  be  lengthened  as  the  chicks  become 
accustomed  to  being  outdoors. 

BLACKHEAD    IN   TURKEYS 

The  cause  of  this  disease  is  a  small  parasite  present  in  the  intestines 
and  liver  of  diseased  birds.*  The  birds  become  infected  by  eating  soil, 
food,  water,  etc.,  contaminated  by  the  droppings  of  diseased  birds. 
The  disease  is  most  dangerous  to  birds  between  the  ages  of  two  weeks 
and  six  months.  The  symptoms  are  droopiness  and  diarrhoea.  The 
head  may  or  may  not  become  dark  in  color.     On  postmortem  exam- 


*  Smith  and  Graybill,  in  their  experiments  with  blackhead,  found  it  impossible 
to  produce  the  disease  in  turkeys  by  feeding  infective  material  unless  cecum  worms 
were  present  in  the  ceca. 


28 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 


ination  yellow  circular  spots  amy  be  found  on  the  liver  and  ulcers 
in  the  walls  of  the  blind  pouches  of  the  intestines.  It  is  frequently 
impossible  to  find  any  lesions  in  young  poults  which  die  from  black- 
head. 

Birds  which  do  not  die  from  the  disease  are  apt  to  be  carriers 
of  the  parasite  as  long  as  they  live  and  it  is  by  this  means  that  the 
disease  is  usually  transmitted  to  young  turkeys.  If  young  turkeys  are 
kept  on  ground  which  has  been  contaminated  by  an  infected  flock  or 
brooded  by  hens  which  have  survived  an  outbreak  of  the  disease,  they 
are  very  liable  to  become  infected. 

Success  in  controlling  the  disease  among  turkeys  raised  in  con- 
finement has  been  obtained  bv  the  following  feeding  method:  After 


n      INCHES 
Z~i +— 

Knfec-'    - 

— -2__, — j — , — 

jf    •  \ 

SELr    - 

jF 

*fe 

*fj 

1 

mm 

r     A 

«T 

-  y 

\ 

fc§L 

-.     y: 

m  ■ 

Jr 

Fig.  24. — Lesions  of  blackhead  in  the  liver  of  a  turkey. 


the  turkeys  are  old  enough  to  leave  the  brooder  their  food  consists 
entirely  of  sour  milk  or  butter-milk  kept  before  them  all  the  time,  and 
a  restricted  amount  of  whole  gratoi.  No  mash  or  water  is  allowed. 
By  following  this  method  turkeys  have  been  successfully  raised  in 
contaminated  yards  for  several  years.  This  method  would  be  difficult 
to  apply  in  turkeys  raised  on  range. 

For  controlling  the  disease  among  birds  raised  on  range,  ipecac  has 
recently  been  highly  recommended  by  a  turkey  raiser  of  this  state. 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


29 


This  is  administered,  as  follows :  To  each  unit  of  20  turkeys  give  two 
teaspoonfuls  of  powdered  ipecac  in  the  mash,  twice  a  week  from  the 
time  the  birds  are  two  weeks  old  until  three  months  old.  After  that 
time  the  dosage  may  be  reduced  to  one  teaspoonful  every  ten  days  for 
the  same  unit  of  turkeys.  It  was  also  claimed  that  tincture  of  ipecac 
administered  in  five-drop  doses  three  times  daily  was  valuable  for  the 
treatment  of  visibly  sick  birds. 


Fig.  2o. — Ulcers  in  the  Avails  of  ceca  or  blind  pouches  of  a  turkey  with  blackhead. 


30 


UNIVERSITY   OF    CALIFORNIA EXPERIMENT   STATION 


COMMON    DISEASES    OF    BIRDS 

Most ' '  common ' '  or  non-infectious  diseases  of  birds  are  of  an  intes- 
tinal origin,  that  is,  due  primarily  to  indigestion.  Therefore,  many 
birds  that  become  droopy  and  which  would  die  if  left  alone  may 
recover  if  treated  properly.  It  is  a  good  practice  to  remove  all  droopy 
birds  from  a  flock  and  give  them  one-half  or  one  ounce  of  castor  oil. 
Castor  oil  can  be  safely  given  through  a  rubber  tube  attached  to  the 
nozzle  of  a  hard-rubber  veterinary  dose  syringe  of  a  suitable  capacity 
and  passed  down  the  throat  into  the  crop  (Fig.  26).     If  the  practice 


Fig.  26. — A  safe  method  of  administering  caster  oil  or  other  liquid  medicine 
to  a  fowl. 


ClECULAR  251]  POULTRY  DISEASES  AND  PARASITES  31 

of  giving  castor  oil  to  all  droopy  birds  is  followed,  the  mortality  can 
be  greatly  decreased.  It  is  always  advisable  to  remove  any  sick  birds 
from  the  flock,  no  matter  what  the  cause  of  the  sickness  may  be.  If 
this  practice  is  strictly  adhered  to  it  will  be  a  great  assistance  in  con- 
trolling any  infectious  disease  which  may  occur  in  the  flock. 

LICE 

These  insects  can  be  distinguished  from  all  other  parasites  on  the 
body  by  the  fact  that  they  have  three  pairs  of  legs  and  their  bodies, 
divided  into  three  sections,  the  head,  thorax,  and  abdomen,  are  flat- 
tened dorso-ventrally,  i.e.,  as  if  a  flattening  force  had  been  applied 
on  their  backs.  They  are  seldom  over  %6  of  an  inch  in  length  and  of 
a  yellow  or  grayish  color,  sometimes  ornamented  with  dark  stripes  but 
never  uniformly  dark  brown  or  red.  Parasites  of  these  latter  colors 
may  be  fleas,  mites,  or  ticks. 

The  entire  life  of  lice,  including  the  egg  stage,  is  spent  on  the 
body  of  the  birds.  It  is  only  by  accident  that  the  parasites  leave  their 
hosts  except  to  migrate  to  other  hosts  of  the  same  species.  The  eggs 
require  about  a  week  to  hatch  after  which  maturity  is  reached  in  about 
two  weeks. 

None  of  the  present-day  remedies  are  harmful  to  the  egg  stage. 
This  necessitates  the  use  of  a  substance  that  will  remain  on  the  body 
long  enough  to  kill  the  emerging  young,  or  a  repetition  of  the  treat- 
ment between  8  and  14  days  after  the  first  treatment. 

Sodium  fluoride*  is  the  only  remedy  that  answers  the  first  require- 
ment of  eliminating  all  the  lice  with  a  single  treatment.  It  also  has 
the  advantages  (1)  of  being  safe  to  both  birds  and  operator,  (2)  of 
accomplishing  a  complete  elimination  of  the  lice,  and  (3)  of  being 
suitable  for  baby  chicks  and  setting  hens.  No  other  treatment  com- 
bines these  advantages,  for  which  reason  we  restrict  our  recommenda- 
tions to  this  single  remedy. 

Sodium  fluoride  may  be  obtained  from  drug  stores  as  a  white 
powder  (commercial  form)  or  as  crystals  (chemically  pure).  It  may 
be  applied  in  three  ways,  viz.,  by  the  " pinch  method,"  dusting,  and 
dipping. 

The  "pinch  method"  consists  of  placing  on  the  skin  of  each  fowl 
approximately  ten  ''pinches"  (amount  held  between  thumb  and  fore 
finger)  of  the  commercial  sodium  fluoride,  distributed  on  the  breast, 
eaoh  thigh,  below  the  vent,  on  each  side  of  the  back,  on  the  neck,  on 


*  This  treatment  was  introduced  and  is  highly  recommended  by  the  Bureau  of 
Entomology  of  the  U.  S.  Department  of  Agriculture.  The  writers  have  used  it 
repeatedly  with  unvarying  success. 


32 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 


the  head,  and  finally  one  sprinkled  on  the  underside  of  each  outspread 
wing.  The  birds,  when  treated,  should  be  held  over  a  shallow  pan  or 
newspaper  in  order  that  the  excess  of  the  chemical  may  be  saved. 

Dusting. — The  powdered  sodium  fluoride  is  sometimes  mixed  with 
three  or  four  times  its  bulk  of  flour  or  talc  and  applied  with  a  large 
shaker,  ruffling  the  feathers  of  the  bird  as  the  chemical  is  applied.  This 
procedure  is  not  as  economical  of  material  or  as  efficient  as  the  pinch 
method  and  the  excess  of  chemical  in  the  air  is  irritating  to  birds  and 
operators. 


Fig.  27. — Three  common  species  of  poultry  lice. 

Dipping  in  sodium-fluoride  solution  is  rapidly  becoming  a  standard 
method  of  treatment  among  a  large  group  of  producers  that  have  over- 
come the  poultrymen's  prejudice  against  wetting  their  birds.  In 
California,  birds  may  be  dipped  safely  in  almost  every  month  of  the 
year  by  choosing  a  warm  day  with  little  wind  and  completing  the 
operations  an  hour  or  two  before  sundown  in  order  that  the  fowls 
may  dry  thoroughly  before  roosting  for  the  night.  The  solution 
should  be  prepared  in  a  wooden  container,  avoiding  contact  with  gal- 
vanized iron.  The  ordinary  wooden  wash  tub  is  excellent  for  this 
purpose.  One  ounce  of  the  commercial  sodium  fluoride,  or  two-thirds 
of  an  ounce  of  the  chemically  pure  crystals,  should  be  dissolved  in 
each  gallon  of  tepid  water.  The  best  method  for  dipping  the  birds  is 
to  hold  them  with  the  left  hand  by  both  wings.  They  are  then  placed 
feet  foremost  in  the  warm  dip  and  submerged  until  only  the  head 
remains  above  the  surface.  They  should  be  held  in  this  position  from 
20  to  25  seconds  while  the  feathers  are  ruffled  to  permit  penetration 
of  the  liquid.  Just  before  removal,  the  head  should  be  ducked  under 
the  surface.  The  birds  should  be  held  above  the  clip  for  two  or  three 
seconds  to  allow  them  to  drip  before  releasing  them.     One  hundred 


Circular  251]  POULTRY  DISEASES  AND  PARASITES  33 

birds  will  use  up  approximately  five  gallons  of  dip,  on  which  basis 
material  should  be  available  at  the  start  of  operations  to  keep  the 
dip  replenished. 

The  dipping  method  kills  all  lice  immediately  but  where  it  is 
applied  as  a  powder  three  or  four  days  will  pass  before  elimination  is 
complete.  If  the  birds  are  caught  and  handed  to  the  operator,  from 
100  to  125  birds  an  hour  can  be  treated  by  dipping  or  dusting,  and 
approximately  60  to  75  per  hour  by  the  "pinch"  method. 

Prevention  is  accomplished  to  some  extent  by  supplying  the  birds 
with  ample  dusting  boxes  filled  with  fine  road  dust  to  which  sulfur  or 
tobacco  dust  has  been  added.  The  best  advice,  however,  is  to  treat  all 
new  acquisitions  to  the  flock  before  permitting  them  to  mix  with  the 
clean  birds.  Brooding  hens,  unless  definitely  known  to  be  free  from 
lice,  should  be  treated  before  being  placed  with  newly  hatched  chicks. 
Spraying  the  house  and  roosts  has  little  effect  on  the  lice  problem. 

MITES 

Two  distinct  groups  of  mites  attack  poultry.  One  group  is  migra- 
tory, passing  the  greater  portion  of  its  life,  not  on  the  birds,  but  in 
cracks  and  crevices  about  the  poultry  houses  from  which  they  make 
nightly  raids  upon  the  roosting  poultry  to  suck  blood.  The  other 
group  passes  its  entire  life  history  on  the  birds  by  burrowing  beneath 
the  scales  of  the  legs,  into  the  skin  at  the  base  of  the  feathers,  or  into 
the  shaft  of  the  feathers  themselves. 

The  Scaly  Leg  Mite. — This  parasite  gets  its  name  from  its  habit  of 
burrowing  beneath  the  scales  of  the  leg  where  its  presence  and  activi- 
ties cause  a  lifting  of  the  scales  and  a  swollen  condition  of  the  shank 
which,  in  advanced  cases,  amounts  to  so  pronounced  a  distortion  and 
deformity  that  the  affected  birds  are  unable  to  walk.  The  mites  them- 
selves are  microscopic  and  the  poultry-man  generally  makes  a  diagnosis 
of  the  trouble  by  observing  the  symptoms  noted  above. 

Treatment  consists  of  dipping  the  legs  of  the  birds  in  a  mixture  of 
equal  parts  of  crude  oil  and  raw  linseed  oil,  taking  precautions  to 
avoid  wetting  the  legs  above  the  scaly  portion.  This  treatment  should 
be  repeated  in  about  three  weeks  unless  marked  improvement  is  noted. 
This  is,  however,  seldom  necessary. 

Prevention. — The  legs  of  newly  acquired  birds  should  be  observed 
carefully  in  order  that  infected  birds  may  be  segregated  and  treated 
before  being  placed  with  the  clean  flock. 

The  Depluming  Mite  is  a  microscopic  parasite  which  burrows  into 
the  skin  at  the  base  of  the  feathers,  producing  an  intense  itching  which 


34 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 


causes  the  birds  to  pluck  out  the  feathers,  leaving  nude  areas  at  the 
more  severely  infested  places.  No  general  treatment  is  available,  but 
individual  birds  may  be  cured  by  the  thorough  application  at  intervals 
of  about  five  days,  of  a  sulfur  ointment  made  by  mixing  three  parts 
of  flowers  of  sulfur  with  one  part  of  lard. 

The  Common  Chicken  Mite  is  a  small  grayish  red  mite,  approxi- 
mately of  the  size  of  a  pinhead  when  filled  with  blood.     It  may  be 


Fig.  28. — Photomicrograph  of  the  scaly  leg  mite. 


distinguished  from  the  insect  parasites  by  its  four  pairs  of  legs,  in 
place  of  the  insects '  three,  and  by  the  fact  that  its  body  is  not  divided 
into  separate  subdivisions.  Its  food  is  blood  which  it  draws  from  the 
birds  by  means  of  long  piercing  stylet-like  mouthparts.  Unlike  the 
other  mites  mentioned  above,  it  hides  away  during  the  day  in  cracks 
and  crevices  about  the  hen  house,  migrating  to  the  roosting  birds  at 
night  to  suck  blood.  The  experienced  poultry-man  is  warned  of  their 
presence  by  the  "salt  and  pepper''  marks  on  the  roosts,  tiny  circular 
black  and  white  dots  slightly  smaller  than  "fly  specks"  caused  by 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


35 


the  excrement  of  the  mites.  However,  if  present,  even  a  cursory 
examination  of  a  few  cracks  or  crevices  in  the  vicinity  of  the  roosts 
will  reveal  myriads  of  these  mites. 

Control. — Inasmuch  as  the  mites  are  seldom  found  on  the  bodies 
of  the  birds  during  the  day,  except  in  the  first  feeding  period  when 
they  sometimes  remain  attached  for  a  night  and  a  day,  or  in  dark 
nest  boxes,  control  measures  are  directed  most  advantageously  against 
the  hiding  places.  A  thorough  clean-up  of  the  premises  to  which  the 
birds  have  access,  together  with  the  elimination  of  every  useless  article 
therein,  such  as  boxes,  coops,  boards,  etc.,  is  the  first  step.    Old  nesting 


Fig.  29. — The  common  poultry  mite  greatly  enlarged. 


material  should  be  burned  and  if  the  infestation  is  severe,  roosts  and 
nests  should  be  dismantled  to  be  replaced  by  construction  that  will 
facilitate  future  clean-ups.  Methods  must  now  be  directed  against  the 
cracks  and  crevices  of  the  floors,  walls,  and  even  the  roof  of  the  poultry 
house.  In  heavy  infestations  the  mites  sometimes  migrate  to  the  out- 
side of  the  house  when  the  inside  is  sprayed.  They  should  be  looked 
for  along  the  cracks  on  the  outside  and,  if  present  there,  a  spraying 
of  the  outside  will  be  decidedly  worth  while.  The  most  efficient  man- 
ner of  accomplishing  this  end  is  by  the  use  of  liquid  insecticides 
applied  preferably  by  "bucket"  or  "knapsack"  spray  pumps.  A 
coarse  spray  is  most  effective  and  should  be  applied  to  each  area  from 
several  different  angles  to  insure  penetration  into  all  hiding  places. 
Many  of  the  existing  sprays  are  efficient.  Any  of  the  dips  used  on 
domesticated  animals  made  up  in  a  slightly  stronger  solution  than 


36  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 

directed  for  the  dipping  of  domesticated  animals  will  give  fairly  satis- 
factory results.  The  most  satisfactory  of  all  applications,  however, 
are  the  wood  preservers  similar  to  "  CarboUneum"  that  have  the  coal- 
tar  product  anthracene  oil  as  a  base.  These  have  the  advantage  of 
being  effective  over  a  long  period  and  of  soaking  into  the  wood  rapidly 
without  leaving  a  greasy  residue  to  soil  the  feet,  feathers  and  eggs  of 
the  birds.  They  should  be  diluted  about  one-half  with  kerosene  to 
facilitate  spraying.  One  careful,  thorough  treatment  generally  proves 
sufficient  with  this  type  of  spray. 

Crude  oil  diluted  sufficiently  with  kerosene  to  make  it  easily 
sprayed  is  efficient  in  killing  the  mites  and  is  sufficiently  durable  but 
leaves  the  roosts,  floors,  etc.,  in  an  oily  condition  so  that  the  flock  must 
be  excluded  from  the  treated  premises  for  some  time  in  order  to  avoid 
soiling  of  feathers  and  eggs. 

Whitewash  containing  3  to  5  per  cent  of  crude  carbolic  acid  kills 
large  numbers  of  mites  but  is  not  nearly  as  effective  as  anthracene  oil 
or  crude  oil. 

Prevention. — The  common  chicken  mite  is  introduced  into  clean 
flocks  in  many  cases  in  contaminated  shipping  coops.  In  some  cases 
the  introduction  may  be  accomplished  by  a  few  young  mites  that  are 
engorging  for  the  first  time  on  the  introduced  fowls.  To  overcome 
this  possibility,  newly  acquired  birds  should  be  kept  in  special  coops 
for  two  or  three  days  before  being  placed  in  clean  houses.  These 
coops  should  then  be  destroyed  or  disinfected  with  boiling  water  or 
with  one  of  the  sprays  suggested  above.  Shipping  coops  from  other 
poultry  plants  should  not  be  left  in  or  near  clean  houses,  nor  should 
second-hand  equipment  be  introduced  unless  the  proper  precautions 
of  disinfection  are  taken.  Mites  will  live  for  from  three  to  five  months 
without  food,  a  fact  which  should  be  considered  when  vacant  buildings 
are  to  be  occupied  by  clean  flocks.  In  cases  where  the  control  of  the 
mite  is  impossible  owing  to  the  character  of  the  quarters  or  lack  of 
them,  some  relief  is  afforded  by  wrapping  the  ends  and  other  points  of 
contact  of  the  roosts  which  have  been  painted  thoroughly  with  crude 
oil,  with  rags  soaked  in  the  same  substance  to  prevent  the  mites  from 
gaining  access  to  the  fowls  after  they  have  roosted.  To  make  this 
procedure  effective  crowding  should  be  discouraged  and  the  back  roosts 
should  not  be  near  enough  to  the  wall  to  permit  the  movement  of  the 
mites  to  the  plumage  of  the  birds. 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


37 


TICKS 

These  parasites  are  closely  related  to  the  mites  but  are  always 
larger,  easily  visible  to  the  naked  eye  and  have  a  thick  leathery  cuticula 
or  skin.  The  only  tick  attacking'  fowls  that  is  of  economic  importance 
is  the  so-called  fowl  tick  or  "blue  bug."  The  adult  tick  is  flat,  egg- 
shaped  in  outline,  dark  brown  in  color,  from  V4  to  %g  of  an  inch  in 
length  and  about  half  as  wide  at  its  widest  part.  Its  habits  are  essen- 
tially like  those  of  the  common  chicken  mite  referred  to  above.  The 
ticks  have  a  remarkable  ability  to  live  for  long  periods  without  food, 
the  specimen  photographed  in  figure  30  having  lived  in  a  tightly 
corked  vial  in  the  author's  desk  for  a  period  of  16  months  without 
food.  Records  are  available  of  adult  ticks  that  have  fasted  for  2% 
years. 


Fig.  30. — Ventral  and  dorsal  view  of  the  poultry  tick  or  blue  bug  enlarged. 


Control — The  procedure  is  the  same  as  in  the  case  of  the  common 
chicken  mite,  with  the  exception  that  the  spray  material  should  be 
stronger  in  every  case  when  the  dilution  is  made  with  water.  The 
wood  preservers  of  anthracene  oil  stand  out  as  the  most  promising 
materials  but  treatment  with  these  often  has  to  be  repeated  at  the  end 
of.  three  or  four  weeks  to  insure  entire  control.  If  sheep  dip  or  other 
stock  dips  are  used  their  dilution  should  be  at  least  as  strong  as  four 
parts  of  water  to  one  of  dip.  When  individual  fowls  are  heavily  in- 
fested with  larvae  taking  their  first  meal,  when  they  remain  attached 
for  several  days,  it  is  advisable  to  dip  them  in  a  2  per  cent  coal-tar  dip 
in  case  the  birds  show  signs  of  weakness.    The  best  practice,  however, 


38  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION 

is  to  merely  segregate  the  infested  birds  for  a  few  days  in  an  isolated 
coop  until  the  ticks  became  engorged  and  drop  off  when  the  birds  may 
be  returned  to  the  flock  and  the  coop  destroyed  or  disinfected  with 
boiling  water  or  some  of  the  sprays  mentioned  above. 

Prevention. — The  procedure  here  is  also  much  the  same  as  in  the 
case  of  the  common  mite  mentioned  before.  The  period  of  quarantine 
mentioned  for  the  previous  mite  must,  however,  be  lengthened  to  five 
or  six  days  in  the  case  of  the  poultry  tick,  but  may  be  eliminated 
entirely  from  the  standpoint  of  tick  prevention  by  a  careful  exam- 
ination of  the  thighs,  breast  and  sides  for  the  round  bluish-red  larval 
ticks  that  can  be  easily  seen  on  account  of  the  contrasting  color  of  their 
bodies  and  the  skin  of  the  birds. 

FLEAS 

These  insects  may  be  distinguished  by  their  dark  brown  color,  three 
pairs  of  legs,  and  their  laterally  flattened  condition. 

The  Sticktight  Flea,  although  parasitic  on  dogs  and  cats,  finds  its 
best  host  in  poultry.  This  flea  remains  attached  to  the  host  throughout 
its  adult  life.  In  poultry  they  are  generally  located  about  the  eyes  and 
comb.  The  eggs  laid  by  these  attached  females  fall  to  the  ground  and 
hatch,  or  in  case  the  eggs  are  retained  in  the  burrows  or  ulcers  caused 
by  the  attached  females,  the  larvae  upon  hatching  fall  to  the  ground. 
These  larvae  are  tiny  white,  caterpillar-like  organisms  with  chewing 
mouthparts.  They  subsist  on  the  debris  or  manure  on  the  floors  of 
houses  and  yards.  When  they  have  become  full-grown  as  larvae  they 
spin  a  white  coccoon  in  which  they  change  from  the  larval  stage  to 
that  of  an  adult,  after  which  they  attach  themselves  to  the  skin  of 
their  hosts  to  suck  blood.  The  constant  irritation,  particularly  in 
spots  where  they  are  present  in  large  numbers,  together  with  a  slight 
burrowing  activity  on  the  part  of  the  fleas,  causes  the  formation  of 
ulcers  so  extensive  at  times  that  blindness  and  subsequent  death  is 
produced. 

Control. — The  first  step  in  control  is  to  prevent  further  infestation. 
This  can  be  accomplished  by  a  rigid  clean-up  of  the  floors  of  the  houses 
and  the  pens,  followed  by  a  thorough  spraying  with  kerosene,  crude  oil 
or  kerosene  emulsion.  Nest  boxes  and  dropping  boards  should  receive 
similar  treatment.  Flooding  the  yards  with  irrigation  water  is  said  to 
produce  beneficial  results.  Infested  birds  may  be  relieved  by  dipping 
in  a  2  per  cent  Creolin  solution. 

Other  Fleas. — The  cat  and  dog  flea,  the  human  flea,  and  the  rat  flea 
are  frequent  inhabitants  of  poultry  houses.     These  fleas  attach  them- 


Circular  251]  POULTRY  DISEASES  AND  PARASITES  39 

selves  to  their  hosts  only  momentarily  at  the  time  that  they  suck  blood, 
remaining  unattached  on  the  host's  body  or  leaving  it  entirely  between 
meals.  The  habits  are  otherwise  like  those  of  the  "stick  tight"  men- 
tioned above.  The  control  is  also  similar.  One  precaution  that  applies 
equally  well  to  the  sticktight  flea  is  to  "turn  under"  all  manure  and 
other  scrapings  from  the  poultry  houses  and  yards  that  is  to  be  used 
for  fertilizing  purposes.  The  mere  storing  of  the  manure  outside  the 
house  in  piles  or  spreading  it  on  the  fields  will  not  prevent  the  develop- 
ment of  the  flea  larvae,  and  although  it  will  prevent  them  from  gain- 
ing access  to  confined  fowls,  the  cats,  dogs  and  men  of  the  neighbor- 
hood will  be  the  alternative  recipients  of  their  attentions  unless  the 
manure  is  carefully  turned  under  by  plowing  or  spading.  The  bottoms 
of  nest  boxes  should  be  frequently  and  liberally  sprinkled  with  tobacco 
dust  or  pyrethrum  powder. 


FLIES 

Life  History. — The  common  house  fly  lays  its  eggs  on  freshly 
deposited  manure.  These  hatch  in  about  two  days  into  tiny  glistening 
white,  footless  maggots  that  grow  rapidly  for  approximately  a  week 
until  about  a  half  inch  in  length,  when  they  migrate  from  the  moister 
part  of  the  manure  to  a  drier  portion;  here  they  turn  into  brown, 
barrel-shaped  "pupae,"  from  which  they  emerge  as  full  grown  flies  in 
about  four  days. 

The  blow  flies,  flesh  flies,  buzz  flies  or  meat  flies,  as  they  are  vari- 
ously called,  will  also  breed  in  chicken  manure,  but  prefer  the  bodies 
of  dead  birds  left  exposed  on  the  ground  or  buried  in  shallow  holes. 

When  garbage  is  fed,  unless  extra  precautions  are  taken,  fly  breed- 
ing will  occur  in  the  garbage  itself  and  even  in  moist  soil  that  has 
become  saturated  with  nitrogenous  material. 

Control. — Removal  of  the  manure  from  the  poultry  houses  and 
yards  at  intervals  of  less  than  seven  days  is  the  first  essential.  Its 
disposal  may  be  accomplished  in  several  ways.  In  truck  and  fruit 
regions  it  has  a  very  definite  cash  value  if  protected  from  the  rain 
and  if  the  ' '  droppings ' ' — scrapings  from  the  dropping  board,  and  the 
"sweepings" — material  from  floors  and  yards,  are  segregated  in  fly- 
tight  bins  and  collected  at  frequent  intervals.  Many  producers  accom- 
plish the  same  result  by  spreading  the  manure  daily  on  plots  to  be 
fertilized  in  a  thin  layer  that  will  rapidly  dry  out.  The  fly  larvae  will 
be  destroyed  by  the  drying  but  it  should  be  plowed  under  about  once 
a  week  to  avoid  the  emergence  of  fleas. 


40  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 

The  maggot  trap  is  another  very  effective  method  of  fly  control 
where  poultry  manure  is  concerned.  This  consists  of  a  concrete  pan 
about  9'  X  12'  X  6"  deep  with  4"  walls.  This  is  kept  filled  with  water 
to  which  a  film  of  oil  is  added.  A  table  with  legs  a  foot  and  a  half 
high  and  slightly  smaller  in  area  than  that  of  the  pan  is  placed  in  the 
pan.  The  top  of  the  table  is  made  of  inch  square  pieces  spaced  their 
own  width  apart,  leaving  a  latticed  appearance,  and  covered  with 
straw  to  prevent  the  manure  from  falling  through.  The  manure  is 
then  placed  on  this  table  or  rack  and  moistened  enough  to  make  it 
thoroughly  wet  but  not  dripping.  Each  addition  is  treated  in  the 
same  way,  the  whole  deposit  being  kept  wet  at  all  times.  The  fly 
larvae  flourish  under  this  treatment  but  when  ready  to  pupate  their 
search  for  a  dry  place  ends  invariably  in  a  fall  to  the  oil-filmed  water 
in  the  pan  below.  If  the  mass  of  manure  is  kept  wet,  this  method  will 
return  a  hundred  per  cent  efficiency. 

Dead  fowls  should  be  disposed  of  through  the  garbage  collection 
system  in  cities  or  towns,  but  in  the  rural  districts,  incineration  is  just 
as  effective.  If  it  is  necessary  to  bury  dead  animals,  a  hole  at  least 
a  foot  and  a  half  deep  should  be  prepared,  the  body  covered  with 
crude  oil  and  the  ground  above  well  tamped. 

TAPEWORMS 

The  effect  of  an  infestation  of  tapeworms  in  poultry  is  so  insidious 
that  the  cause  is  often  either  not  suspected  or  entirely  overlooked. 
These  worms,  inhabitants  of  the  intestines,  when  full  grown,  range 
from  almost  microscopic  size  to  ten  inches,  depending  on  the  species. 
They  have  a  ' '  head ' '  or  scolex  by  which  they  attach  themselves  to  the 
walls  of  the  intestine.  Behind  this  are  a  series  of  segments  which 
have  their  origin  just  behind  the  scolex  at  the  "neck."  As  these 
segments  grow  older  and  new  ones  are  formed  at  the  "head"  end, 
they  move  away  from  this  end  and  finally,  when  mature,  i.e.,  when 
full  of  ' '  eggs, ' '  slough  off  and  pass  from  the  body  of  the  host  with  its 
feces.  If  these  "eggs"  are  eaten  by  some  other  animal  which  acts  as 
an  intermediary  host,  the  young  tapeworm  develops  up  to  a  certain 
stage  in  its  body,  where  it  remains  dormant  until  eaten  by  poultry, 
when  the  larval  tapeworm  again  becomes  active,  further  development 
takes  place  and  the  worm  becomes  mature,  sloughing  off  more  segments 
of  mature  "eggs." 

The  Common  Poultry  Tapeworm  is,  as  its  name  implies,  our 
commonest  tapeworm.  Investigations  at  the  Oklahoma  Experiment 
Station  have  demonstrated  apparently,  without  leaving  any  doubt, 
that  the  larvae  of  houseflies  feeding  in  poultry  manure  become  the 


Circular  251]  POULTRY  DISEASES  AND  PARASITES  41 

intermediary  hosts.  Chickens  become  infested  by  eating  these  larvae 
or  the  adult  flies  that  they  become. 

Other  Tapeworms. — Several  other  tapeworms  are  recorded  from 
the  United  States.  One  is  contracted  by  eating  infected  larval  or  adult 
stable  flies,  another  through  snails,  one  through  slugs,  and  the  hosts 
of  the  others  are  still  in  doubt,  although  dung  beetles  have  been 
suggested. 

Control. — Where  the  flocks  are  confined  to  yards  and  houses  from 
which  the  manure  with  its  infected  fly  larvae  is  removed  promptly, 
and  efficiently  disposed  of,  and  where  other  intermediary  carriers  are 
not  so  apt  to  occur,  little   trouble  results  from  tapeworms.     Very 


Fig.  31. — Inside  of  a  hen's  intestine,  showing  attached  tape  worms,  2  X.  (At 
post  mortem  examination,  the  worms  appear  much  longer  and  more  transparent, 
but  contract  and  become  whiter  at  death.) 

little  has  been  done  in  regard  to  the  treatment  of  poultry  tapeworms. 
The  Oklahoma  Station  recommends  cooking  a  mash  of  one  gallon  (for 
15  birds)  of  whole  grain  to  which  has  been  added  a  small  tablespoon- 
ful  of  concentrated  lye.  After  a  fifteen  hour  fast,  the  cooled  mash  is 
fed  to  the  birds,  allowing  them  to  eat  as  much  as  they  wish  and  pro- 
viding plenty  of  water.  The  treatment  may  be  repeatejd  in  twenty- 
four  hours.  They  report  exceedingly  satisfactory  results.  Turpentine 
in  !/4  to  y2  ounce  doses  administered  to  the  birds  individually,  followed 
by  a  40  to  50  grain  dose  of  Epsom  salts  will  also  give  good  results  if 
the  number  of  fowls  to  be  treated  is  small  enough  to  make  such  indi- 
vidual treatment  feasible.  Freshly  ground  areca-nut  in  30  to  50  grain 
doses  is  also  said  to  be  effective.  Treatment  is  facilitated  by  mixing 
the  required  amount  of  the  powder  into  pellets  with  butter  or  lard. 


42 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION 


ROUNDWORMS 

This  name  is  commonly  applied  to  the  slender  wire-like  worms 
from  iy2  to  3  inches  long  that  are  commonly  found  in  the  intestines. 
Affected  pullets  are  stunted  in  growth  and  their  plumage  is  bedraggled 
and  soiled.  Older  hens,  although  seldom  seriously  affected,  have  a 
generally  unkempt  appearance  and  their  egg  production  is  below 
normal.  The  mature  worms  in  the  intestine  deposit  eggs  which  pass 
out  of  the  body  of  the  birds  in  the  droppings.  After  a  few  days' 
exposure  to  the  air  a  young  worm  develops  in  the  egg  which,  if  eaten 
by  the  bird,  promptly  hatches  and  soon  becomes  a  mature  worm  in 


Fig.  32. — Section  of  intestine  showing  roundworms  protruding  from  the  cat  ends. 


the  bird's  intestine.  These  eggs  are  very  resistant  and  will  persist  in 
the  ground  in  a  healthy  condition  for  months  and  even  years.  No 
practical  treatment  is  known  at  present  for  destroying  these  eggs  on 
infested  ground.  For  this  reason  our  greatest  trust  must  be  placed 
in  the  repeated  treatment  of  the  birds. 

Tobacco  is  the  most  successful  remedy  that  has  yet  been  found  for 
removing  these  worms.  It  is  generally  administered  in  the  form  of 
ground  tobacco  dust  mixed  with  the  mash  at  the  rate  of  one  pound 
of  dust  to  50  pounds  of  dry  mash,  feeding  this  treated  mash  for  from 
three  to  four  weeks.  Growing  birds  kept  in  infested  yards  may  require 
a  repetition  at  intervals  of  about  six  weeks.    There  is  a  great  variation 


Circular  251] 


POULTRY  DISEASES  AND  PARASITES 


43 


in  the  different  tobacco  dusts  on  the  market,  both  in  strength  and 
origin,  as  some  are  sweepings  from  manufacturing  plants,  some  are 
milled  in  combination  with  other  substances,  while  the  most  desirable 
are  100  per  cent  ground  tobacco.  Tobacco  dust  also  loses  its  strength 
by  exposure  to  air  or  moisture,  which  necessitates  buying  in  quantities 
just  sufficient  for  the  present  need.  Tobacco  dust  is  now  being  gen- 
erally handled  by  feed  stores  and  should  be  retailed  in  containers 
bearing  the  analysis  of  the  amount  of  nicotine  present. 

Work  is  now  being  carried  on  at  this  Experiment  Station  to  deter- 
mine an  exact  treatment ;  until  this  work  is  completed  the  above  treat- 
ment is  recommended  wherever  the  nicotine  content  does  not  exceed 
1.5  per  cent,  in  which  case  the  amount  mixed  with  each  50  pounds  of 
mash  should  be  correspondingly  reduced  if  laying  hens  are  being 
treated,  since  an  excess  of  tobacco  will  cause  a  reduction  in  the  egg 
production.  With  young  birds,  however,  a  stronger  dose  and  a  corre- 
spondingly shorter  period  of  treatment  may  be  utilized  with  no  harm- 
ful effects. 

Wherever  possible  chicks  and  young  pullets  should  be  on  land  that 
has  not  been  occupied  by  hens  for  at  least  a  year  and  their  buildings 
carefully  cleaned  and  washed  before  occupancy.  Later  troubles  may 
be  avoided  if  every  flock  of  pullets  suspected  of  having  worms  is  given 
a  thorough  tobacco  treatment  before  they  commence  to  lay. 


Fig.  33. — Highly  magnified  eggs  of  cecum  worm  and  intestinal   round   worm 
which  pass  out  in  the  droppings  and  contaminate  the  yards. 


44  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


CECUM   WORMS 

These  tiny  parasites,  measuring  from  y2  to  %  of  an  inch  in  length, 
are  found  in  the  ceca  or  "blind  guts"  of  the  intestine.  On  account  of 
their  small  size  they  are  often  overlooked  by  the  poultryman  or  taken 
for  the  young  of  intestinal  round  worms  and  their  harmful  effects  are 
minimized  or  ignored.  Their  presence  on  the  walls  of  these  organs 
interrupts  their  normal  functioning  and  in  the  case  of  baby  chicks, 
may  result  in  death  as  early  as  the  tenth  day.  On  account  of  their 
sheltered  position,  they  are  very  hard  to  remove.  Large  doses  of 
tobacco  dust  have  been  known  to  cause  their  removal  but  no  definite 
data  on  this  point  are  available  at  the  present  time.  Infection  occurs 
in  the  same  manner  as  outlined  for  the  round  worms  and  preventive 
measures  should  be  taken  with  chicks  and  pullets  along  the  same  lines. 


